England's Carl Mason edged one step closer to winning his first major title when he carded a five under par 65 to move into a one stroke lead heading into the final round of the Senior British Open, presented by MasterCard, at the Westin Turnberry Resort in Ayshire, Scotland.

The 50 year-old Mason, who won on his last time out at The Mobile Cup, Buckinghamshire, recorded six birdies and dropped just one shot. However, for a while at least, his exploits were still almost overshadowed by a rampaging Jack Nicklaus, who played his first 14 holes in six under par before dropping two shots down the stretch.

Mason will go out at 11.15 am tomorrow on 14 under par 195 and one shot ahead of America's DA Weibring, who also carded a 65. Tom Kite, Bruce Summerhays and Tom Watson share third place on 11 under par 199, with Jim Colbert on 200 and another American, Mark McCumber on 201.

Meanwhile, Nicklaus is tied for 9th after completing a three under par 67. The Golden Bear is also second in the race for the Hardys Wines Super Seniors prize awarded to the leading competitor aged 60 or over, four shots behind Colbert

Mason went out with a one shot lead and consolidated his position with birdies on the fifth and the seventh holes. He carded two more birdies on the 415 yard tenth and the 175 yard 11th but then dropped his first shot for 43 holes when he drove into trouble on the 412 yard 14th and had to take a penalty drop.

That error meant that the Englishman was caught by both Weibring and Kite but he pulled ahead again when Weibring failed to match his second successive birdie on the 18th and Kite recorded an ugly double bogey on the 17th.

"I have to admit I felt a bit flat during the first few holes which I don't suppose was all that surprising considering I played the first two rounds with Jack Nicklaus and Tom Watson," said Mason. "But the birdies on five and seven settled me down and I was fine after that."

"I am thoroughly enjoying the week," he added. "It's been a great experience and I would like to think I can keep things going."

“Tomorrow I will be flying the flag for the European Seniors Tour. It looks like it's going to me against all the Americans which is going to be a lot of fun."

Mason’s nearest challenger is 50 year-old Weibring, a winner of five US PGA Tour titles who, like the leader, has played in only a handful of Seniors Tour events after turning 50 at the end of May.

Weibring began his round with birdies on the first and the fifth. He dropped a shot on the sixth but then stormed home with further birdies on the seventh, 12th, 13th and 17th.

“I played just as well as I did when I scored yesterday,” said the American. “When we started out I felt there would be some low scores but little did I know one of them would come from me. I thought the committee might tuck the pins a little bit more. They did tuck a few more but the also gave us a chance to play.”

For a while at least, it appeared that both Tom Watson and Jack Nicklaus would go into the final round within one or two shots of the leader but, while Watson achieved that objective, Nicklaus was left to rue an untidy finish.

“I am very pleased with the position I’m in,” said Watson. “Mason is the man to beat because he’s making so few mistake but I still like my chances if I can get off to a good start tomorrow. The title is there to be grabbed.”

“I could use a lot of words for how I finished but you wouldn’t be able to print any of them,” bemoaned Nicklaus. “It’s very irritating. I am hitting the ball better than I have done for the whole of the year but I am not converting nearly enough of the chances I’m making.”

A total of seven European Seniors Tour members go into the final round within the top-20 on the leaderboard. Australia’s Brian Jones carded a 65 to move up to eighth place on seven under par 203 while England’s Bob Cameron and Denis Durnian were one place further back on 204. Further down the list, Australia’s Terry Gale and Scotland’s Russell Weir were tied for 14th while New Zealand’s Bob Charles shared 19th place with America’s Dana Quigley on 206. Charles’s fine showing perpetuated his magnificent record in this championship, the 67 year-old left-hander having won twice, finished second six times and accumulated 14 top-10 finishers.

Ireland’s Arthur Pierse went into the final round knowing that, as the only amateur to make the cut, he was guaranteed the Gold Medal, awarded to the leading part-timer. He had opened with rounds of 72 and 67 but dropped back into a share of 49th place after carding a third round three over par 73.